Programming Field

Ipconfig - DOS/Command Prompt Reference

[Windows NT series/XP or later] Displays the IP address assigned to the network adapter and performs related operations.

Syntax

ipconfig[.exe] [/allcompartments]
    [/all |
    /renew [<adapter>] | /renew6 [<adapter>] |
    /release [<adapter>] | /release6 [<adapter>] |
    /flushdns | /displaydns | /registerdns |
    /showclassid <adapter> | /showclassid6 <adapter> |
    /setclassid <adapter> [<classid>] |
    /setclassid6 <adapter> [<classid>]]

* Options other than /allcompartments can be used individually (or none at all).

Options

<adapter> For each option, specifies the network adapter name with <adapter>. The adapter name corresponds to the name displayed in ‘Network and Sharing Center’ → ‘Change adapter settings’ in the Control Panel. (It is also possible to change the name from there.)
/allcompartments [Windows Vista or later] Operates on all network compartments (displays information or changes settings).
/all Outputs detailed information for each adapter. If /all is not specified, it will output information such as IP addresses and default gateways.
/renew [<adapter>]

Refreshes the assigned IP address (IPv4) for <adapter>. In the case of automatic allocation, a different address may be assigned than before.

If <adapter> is omitted, it refreshes the addresses for all available adapters.
/renew6 [<adapter>] [Windows Vista or later] Similar to /renew, but refreshes IPv6 addresses.
/release [<adapter>] Releases the assigned IPv4 address for <adapter>. After releasing, a temporary IP address may be assigned until refreshed with `/renew`.
/release6 [<adapter>] [Windows Vista or later] Similar to /release, but releases IPv6 addresses.
/flushdns Purges the DNS resolver cache. This is used when you want to query the DNS server again for the address of a domain name.
/displaydns Displays a list of the contents of the DNS resolver cache. Since it shows all cached domain names, the output may be extensive.
/registerdns Performs a re-registration of client information (DNS names) registered with the DNS server. Administrative privileges are required to execute this command.
/showclassid <adapter> Displays all DHCP class IDs assigned to the client of <adapter>. Use /setclassid to configure.
/showclassid6 <adapter> [Windows Vista or later] Similar to /showclassid, but displays DHCPv6 class IDs.
/setclassid <adapter> [<classid>] Sets the DHCP class ID for the client of <adapter>. The class ID must be one recognized by the DHCP server. If <classid> is omitted, it can be set to none. Administrative privileges are required to execute this command.
/setclassid6 <adapter> [<classid>] [Windows Vista or later] Similar to /setclassid, but it sets the DHCPv6 class ID. Administrative privileges are required to execute this command.

Details

Usage of Ipconfig

Ipconfig mainly provides functionality related to network adapters, including the following:

  • Displaying, renewing, and releasing the current values of IP addresses (no option, /all, /renew, /renew6, /release, /release6)
  • Operations related to DNS (/flushdns, /displaydns, /registerdns)
  • Configuring DHCP class ID (/showclassid, /showclassid6, /setclassid, /setclassid6)

Ipconfig can be used to check whether the adapter is functioning properly and perform basic maintenance when unable to connect to the network or the internet.

Samples

Sample 1

ipconfig /renew Wi-Fi

Refreshes the IPv4 address assigned to the adapter named ‘Wi-Fi’.

Sample 2

ipconfig /flushdns

Clears the DNS resolver cache, forcing new address queries when resolving hostnames for subsequent connections.